148 research outputs found
Rapid recurrence of a malignant meningioma: Case report
This short report presents a case that developed rapid recurrence of a malignant meningioma. The meningioma was located on the right temporal lobe and total removal (Simpson grade-II) was performed. Radiotherapy was not given and the lesion recurred within four months. The MIB-1 (Ki-67) index was 30 % and the tumor fulfilled all the criteria of anaplasia. After the second surgery, patient was transferred to the Radiation Oncology for radiotherapy. Should we questioned the extent of surgery? Neurosurgeons should be careful and close follow-up the patients with malignant meningioma
Pediatric meningiomas in The Netherlands 1974–2010: a descriptive epidemiological case study
The purpose of this study was to review the epidemiology and the clinical, radiological, pathological, and follow-up data of all surgically treated pediatric meningiomas during the last 35 years in The Netherlands. Patients were identified in the Pathological and Anatomical Nationwide Computerized Archive database, the nationwide network and registry of histopathology and cytopathology in The Netherlands. Pediatric patients of 18 years or younger at first operation in 1974-2009 with the diagnosis meningioma were included. Clinical records, follow-up data, radiological findings, operative reports, and pathological examinations were reviewed. In total, 72 patients (39 boys) were identified. The incidence of operated meningiomas in the Dutch pediatric population is 1:1,767,715 children per year. Median age at diagnosis was 13 years (range 0-18 years). Raised intracranial pressure and seizures were the most frequent signs at presentation. Thirteen (18 %) patients had neurofibromatosis type 2 (NF2). Fifty-three (74 %) patients had a meningioma World Health Organization grade I. Total resection was achieved in 35 of 64 patients. Fifteen patients received radiotherapy postoperatively. Mean follow-up was 4.8 years (range 0-27.8 years). Three patients died as a direct result of their meningioma within 3 years. Four patients with NF2 died as a result of multiple tumors. Nineteen patients had disease progression, requiring additional treatment. Meningiomas are extremely rare in the pediatric population; 25 % of all described meningiomas show biological aggressive behavior in terms of disease progression, requiring additional treatment. The 5-year survival is 83.9 %, suggesting that the biological behavior of pediatric menigiomas is more aggressive than that of its adult counterpart
A comprehensive review on rheological studies of sludge from various sections of municipal wastewater treatment plants for enhancement of process performance
Large quantities of sludge is generated from different sections of a wastewater treatment plant operation. Sludge can be a solid, semisolid or liquid muddy residual material. Understanding the flow behaviour and rheological properties of sewage sludge at different sections of a wastewater treatment plant (WWTP) is important for the design of pumping system, mixing, hydrodynamics and mass transfer rates of various sludge treatment units, optimization of conditioning dose and for sustainable sludge management. The current article provides a comprehensive review on up to date literature information on rheological behaviour of raw primary sludge, excess activated sludge, thickened excess activated sludge, mixture of raw primary and thickened excess activated sludge (mixed sludge), digested sludge, and biosolid under the influence of different operating parameters and their impacts on process performance. The influences of various process parameters such as solid concentration, temperature, pH, floc particle size, primary to secondary sludge mixing ratio, aging and conditioning agent doses on the rheological behaviour of sludge from different treatment units of WWTPs are critically analysed here. Yield stress was reported to increase with increasing solid concentration for all types of sludge whereas viscosity showed a decreasing trend with decreasing total solid concentration and percentage of thickened excess activated sludge in the mixture. Temperature showed an inverse relationship with yield stress and viscosity. Viscosity was reported to be decreased with decrease in pH. The effect of various conditioning agents on the rheological behaviour of sludge are also discussed here. The applicability and practical significance of various rheological models such as Bingham, Power Law (Ostwald), Herschel-Bulkley, Casson, Sisko, Careau, and Cross models to experimental rheological characteristics of various sludges were presented here. The reported results on various rheological parameters such as shear stress, yield stress, flow index, infinite, zero-rate viscosity, and flow consistency index of different sludge types obtained from the best fitted model were also compiled here. Conclusions have been drawn from the literature reviewed and few suggestions for future research direction are proposed
Effect of organic matter on phosphorus recovery from sewage sludge subjected to microwave hybrid pretreatment
Benign external hydrocephalus: a review, with emphasis on management
Benign external hydrocephalus in infants, characterized by macrocephaly and typical neuroimaging findings, is considered as a self-limiting condition and is therefore rarely treated. This review concerns all aspects of this condition: etiology, neuroimaging, symptoms and clinical findings, treatment, and outcome, with emphasis on management. The review is based on a systematic search in the Pubmed and Web of Science databases. The search covered various forms of hydrocephalus, extracerebral fluid, and macrocephaly. Studies reporting small children with idiopathic external hydrocephalus were included, mostly focusing on the studies reporting a long-term outcome. A total of 147 studies are included, the majority however with a limited methodological quality. Several theories regarding pathophysiology and various symptoms, signs, and clinical findings underscore the heterogeneity of the condition. Neuroimaging is important in the differentiation between external hydrocephalus and similar conditions. A transient delay of psychomotor development is commonly seen during childhood. A long-term outcome is scarcely reported, and the results are varying. Although most children with external hydrocephalus seem to do well both initially and in the long term, a substantial number of patients show temporary or permanent psychomotor delay. To verify that this truly is a benign condition, we suggest that future research on external hydrocephalus should focus on the long-term effects of surgical treatment as opposed to conservative management
Cervical cord tethering and congenital mirror movements: is it an association rather than a coincidence?
Two unusual cases of cervical cord tethering associated with mirror movements of the hands are presented. A brief discussion of the literature pertaining to mirror movements is included. It is concluded that the association of cervical cord tethering and mirror movements can be more than a coincidence
The effect of pulsed ultrasound exposure on the oxygen dissociation curve of human erythrocytes in in vitro conditions
The P-50 value, a marker for the behavior of the oxygen dissociation curve (ODC) and values of 2,3-diphosphoglyceric acid (2,3-DPG), blood gases and acid base parameters (pH, PCO2, actual HCO3-, base excess, PO2, SO2) and erythrocyte parameters (the number of erythrocyte, hematocrit and hemoglobin values) that are known to effect P-50, were measured before and after ultrasound (US) exposure to examine the effect of pulsed US beams on the ODC of human erythrocytes. Venous blood samples taken from healthy subjects were sonicated at 0degreesC for 30 min by pulsed US beams with a constant frequency of 5 MHz. Experiments showed that the values of pH, actual HCO3-, standard HCO3- base excess, 2,3-DPG and P-50 were changed considerably by pulsed US. Furthermore, correlation calculations were made to find out the relation between the P-50 values and the other parameters. As a result, a significant relation was found between P-50 values and the values of pH, actual HCO3-, PO2, SO2 and 2,3-DPG. In conclusion, we can express that a highly significant increase occurs in P-50 value of venous blood after a pulsed US exposure at a constant frequency of 5 MHz for 30 min under in vitro conditions at 0degreesC. That is hemoglobin becomes suitable for deoxy (tense structure) conformation when blood affinity of O-2 is low. It means that hemoglobin becomes convenient for proton (H+) and CO2 binding. (E-mail: [email protected]) (C) 2002 World Federation for Ultrasound in Medicine Biology
Influence of aging on blood-brain barrier permeability and free radical formation following experimental brain cold injury
The aim of this study is to investigate the effects of experimental cold brain injury on blood-brain barrier integrity, on brain oedema formation, and on lipid peroxidation and to compare the results between the aged and young rats. Cold brain injury was used to create a standard model of brain trauma in old and young rats. Disruption of the blood-brain barrier was analyzed by Evans blue method. Them values of cerebral water content were calculated by using the fresh and dry weights of the cerebral hemispheres. Lipid peroxidation was assessed by measuring the tissue content of malonyl dialdehyde
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